I've seen "no maintenance" systems all my life replace ones that allow you to maintain them. They never last longer. When I finally retired my 1970 ford van after more than a half million miles, it still had the original front wheel bearings (which I could pack) and I had replaced the rear (sealed maintenance free) bearings more times than I can remember. I can still remember a lot of long hikes with an axel on my shoulder to go buy a new sealed bearing and have it pressed on. Same with fans. You used to always have a spot you could oil the bearings and those lasted forever. None of the new ones have such a thing and I'm lucky if they last a year. I'm more than happy to maintain things. I'm not happy when I have to replace them because I couldn't maintain them. Plastic has gotten much better over the years to where in SOME applications it will outlast other materials. But mostly metal will still outlast it. Sometimes by a lot.